Many people wondering what is driving the spike in murders in the US. This dramatic spiked in 2015, with murders increasing 10.8 percent after a few years of small bumps in murders and many years of declining murder rates. This is the biggest jump since 1971.

CCTV America’s Jim Spellman takes a look at the numbers.

There were 15,696 murders in the US in 2015,however murders in the US are way down over the last 20 years. In fact in 1991 when the crack cocaine epidemic swept through many American cities there were about twice as many murders as last year.

The overall picture of crime in the U.S. show that murders are a very small slice of all crimes. Assaults, robbery and rapes make up most of the violent crime in the U.S. Ten of the biggest cities in the US account for most of the increase, including like Baltimore, Chicago and Washington DC.

But other big cities like New York haven’t seen this jump in murders. At least 900 more black men were murdered in 2015 than in 2014.